VD4. Installation and service instructions kv A ka

Transcription

1 VD4 Installation and service instructions kv A ka

2

3 For your safety! Make sure that the installation room (spaces, divisions and ambient) is suitable for the electrical apparatus. Check that all the installation, putting into service and maintenance operations are carried out by personnel with suitable knowledge of the apparatus. Make sure that the standard and legal prescriptions are complied with during installation, putting into service and maintenance, so that installations according to the rules of good working practice and safety in the work place are constructed. Strictly follow the information given in this instruction manual. Check that the rated performance of the apparatus is not exceeded during service. Check that the personnel operating the apparatus have this instruction manual to hand as well as the necessary information for correct intervention. Pay special attention to the danger notes indicated in the manual by the following symbol:! Responsible behaviour safeguards your own and others safety! For any requests, please contact the ABB Assistance Service. 1

4 Index I. Introduction 3 II. Programme for environmental protection 3 1. Packing and transport 4 2. Checking on receipt 4 3. Storage 4 4. Handling 5 5. Description General information Reference Standards Fixed circuit-breaker Withdrawable circuit-breaker Characteristics of the electrical accessories Instructions for circuit-breaker operation Safety indications Operating and signalling parts Circuit-breaker closing and opening operations Installation General Installation and operating conditions Preliminary operations Installation of fixed circuit-breaker Installation of withdrawable circuit-breaker Power circuit connection of fixed circuit-breaker Earthing Connection of the auxiliary circuits Overall dimensions 29 Fixed circuit-breakers 29 Withdrawable circuit-breakers for UniGear type ZS1 and UniSafe switchgear Putting into service General procedures Maintenance General Inspection and functional testing Servicing Repairs Application of the standards for X-ray emission Spare parts and accessories List of spare parts 44 2

5 I. Introduction This publication contains the information needed to install medium voltage VD4 circuit-breakers and put them into service. For correct use of the product, please read it carefully. Like all the apparatus we manufacture, the VD4 circuit-breakers are designed for different installation configurations. However, these pieces of apparatus do allow further technical and construction modifications (at the customer s request) to adapt to special installation requirements. Consequently, the information given below may sometimes not contain instructions concerning special configurations. Apart from this manual, it is therefore always necessary to consult the latest technical documentation (circuit and wiring diagrams, assembly and installation drawings, any protection coordination studies, etc.), especially regarding any variants requested in relation to the standardised configurations. Only use original spare parts for maintenance operations. For further information, please also see the technical catalogue of the circuit-breaker and the spare parts catalogue.! All the installation, putting into service, running and maintenance operations must be carried out by suitably qualified personnel with in-depth knowledge of the apparatus. II. Environmental protection programme The VD4 circuit-breakers are manufactured in accordance with the ISO Standards (Guidelines for environmental management). The production processes are carried out in compliance with the Standards for environmental protection in terms of reduction in energy consumption as well as in raw materials and production of waste materials. All this is thanks to the medium voltage apparatus manufacturing facility environmental management system. 3

6 1. Packing and transport The circuit-breaker is shipped in special packing, in the open position and with the springs discharged. Each piece of apparatus is protected by a plastic cover to prevent any infiltration of water during the loading and unloading stages and to keep the dust off during storage. 2. Checking on receipt! Before carrying out any operation, always make sure that the operating mechanism springs are discharged and that the apparatus is in the open position. On receipt, check the state of the apparatus, integrity of the packing and correspondence with the nameplate data (see fig. 1) with what is specified in the order confirmation and in the accompanying shipping note. Also make sure that all the materials described in the shipping note are included in the supply. Should any damage or irregularity be noted in the supply on unpacking, notify ABB (directly or through the agent or supplier) as soon as possible and in any case within five days of receipt. The apparatus is only supplied with the accessories specified at the time of ordering and validated in the order confirmation sent by ABB. The accompanying documents inserted in the shipping packing are: instruction manual (this document) test certification identification label copy of the shipping document electric wiring diagram. Other documents which are sent prior to shipment of the apparatus are: order confirmation original shipping advice notes any drawings or documents referring to special configurations/conditions. 3. Storage When a period of storage is foreseen, our workshops can (on request) provide suitable packing for the specified storage conditions. On receipt the apparatus must be carefully un- Caption A Circuit-breaker rating plate. B Operating mechanism rating plate. 1 Type of apparatus. 2 Symbols of compliance with Standards. 3 Serial number. 4 Circuit-breaker characteristics. 5 Characteristics of the operating mechanism auxiliaries. A 3 4 B 5 CIRCUIT-BREAKER IEC VD4... CEI 17-1 NO.... MASSE... kg RATED VOLTAGE... kv IMPULSE WITHSTAND VOLTAGE ATM.... kv RATED FREQUENCY 50/60Hz RATED NORMAL CURRENT... A SHORT-TIME CURRENT (...s)... ka CLOSING / OPENING TIME... ms BREAKING CAPACITY... ka MAKING CAPACITY... ka AT A VOLTAGE OF... kv OPERATION SEQUENCE O-0,3s-CO-3Min-CO OPERATING MECHANISM IEC EL... CEI NO.... MO... V... MO1... V... 2 packed and checked as described in Checking on receipt (chap. 2). If immediate installation is not possible, the packing must be replaced, using the original material supplied. Insert hygroscopic packets inside the packing, with at least one standard packet for piece of apparatus. Should the original packing not be available and immediate installation is not possible, store in a covered, well-ventilated, dry, dust-free, non-corrosive ambient, away from any flammable materials and at a temperature between 5 C and +45 C. In any case, avoid any accidental impacts or positioning which stresses the structure of the apparatus. MS... V... Manufactured by ABB Fig. 1 4

7 4. Handling Before carrying out any operations, always make sure that the operating mechanism springs are discharged and that the apparatus is in the open position. To lift and handle the circuit-breaker, proceed as follows (fig. 2): use a special lifting tool (1) (not supplied) fitted with ropes with safety hooks (2); insert the hooks (2) in the supports (3) fixed to the frame of the circuit-breaker and lift. Put the hooks (2) into the support holes (3) according to the type of apparatus (see table); on completion of the operation (and in any case before putting into service) unhook the lifting tool (1) and dismantle the supports (3) from the frame. During handling, take great care not to stress the insulating parts and the terminals of the circuit-breaker.! The apparatus must not be handled by putting lifting devices directly under the apparatus itself. Should it be necessary to use this technique, put the circuit-breaker onto a pallet or a sturdy supporting surface (see fig. 3). In any case, it is always advisable to carry out lifting using the supports (3) C B A 3 Fig. 2 Version Pole centre distance Rated current Hole Fixed mm up to 1250 A A Fixed 275 mm from 1600 to 2500 A A Fixed 210 mm from 1600 to 2000 A A Withdrawable 150 mm up to 1250 A A Withdrawable 210 mm from 1600 to 2500 A B Withdrawable 275 mm up to 1250 A B Withdrawable 275 mm from 1600 to 2500 A C Withdrawable 210 mm up to 1250 A C Fig. 3 5

8 5. Description 5.1. General The VD4 series of circuit-breakers are pieces of apparatus under vacuum for indoor installation; for the electrical performances, please refer to the corresponding technical catalogue code 1VCP For special installation requirements, please contact ABB. The following versions are available: fixed withdrawable for UniGear ZS1 type and UniSafe switchgear Reference Standards The VD4 circuit-breakers conform with the IEC , DIN VDE 0670, CEI 17-1 file 1375 Standards and those of major industrialised countries Fixed circuit-breaker The fixed circuit-breaker (fig. 4) is the basic version complete with structure and front protection screen. The fixing holes are made in the lower part of the structure. For the electrical connections of the circuitbreaker auxiliary circuits, the terminal box (10) is available (also see par ). The earthing screw is placed in the rear part of the circuit-breaker. For further details, please see the caption to figure General characteristics of fixed circuit-breakers Circuit-breaker Standards Rated voltage Rated insulation voltage Withstand voltage at 50 Hz Impulse withstand voltage Rated frequency Rated normal current (40 C) Rated breaking capacity (rated symmetrical shortcircuit current) Rated short-time withstand current (3 s) Making capacity Operation sequence Opening time Arcing time Total breaking time Closing time Maximum overall dimensions Pole centre distance Standardised table of dimensions Operating temperature Tropicalisation Electromagnetic compatibility IEC CEI 17-1 (File 1375) Ur [kv] Us [kv] Ud (1 min) [kv] Up [kv] fr [Hz] Ir [A] Isc [ka] Ik [ka] Ip [ka] [O-0,3s-CO-3min-CO] [ms] [ms] [ms] [ms] H [mm] W [mm] D [mm] I [mm] [ C] IEC: IEC: 60694, VD TN7405 TN7406 TN7405 TN7406 TN7407 TN7408 TN7407 TN7408 TN

9 Caption 1 Lever for manual closing spring charging 2 Signalling device for circuit-breaker open/closed 3 Rating plate 4 Opening pushbutton 5 Closing pushbutton 6 Signalling device for closing springs charged/discharged 7 Operation counter 8 Terminals 9 Earthing screw 10 Delivery terminal box 11 Cabling connection 12 Mechanical override for undervoltage release (optional) Fig. 4 VD4 17 VD TN7405 TN7406 TN7405 TN7406 TN7407 TN7408 TN7407 TN7408 TN TN7409 TN7410 TN7409 TN7410 TN7411 TN7411 TN

10 Types of circuit-breakers available in the fixed version VD4 fixed circuit-breaker without bottom and top terminals Ur Isc Rated uninterrupted current (40 C) [A] kv ka H = 461 H = 599 H = 616 H = 631 H = 642 H = 661 Circuit-breaker type D = 424 D = 424 D = 424 D = 424 D = 424 D = 424 u/l = 205 u/l = 310 u/l = 310 u/l = 310 u/l = 310 u/l = 310 l/g = l/g = l/g = l/g = l/g = l/g = I = 150 I = 210 I = 210 I = 275 I = 275 I = 210 I = 275 I = 275 I = 275 W = 450 W = 570 W = 570 W = 700 W = 700 W = 570 W = 700 W = 700 W = VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p275 Notes H = Height of the circuitbreaker. W = Width of the circuitbreaker. D = Depth of the circuitbreaker. u/l= Distance between bottom and top terminal. l/g= Distance between the bottom terminal and the resting surface of the circuit-breaker. I = Pole horizontal centre distance. 17, VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p VD p275 8

11 Standard fittings for fixed circuit-breakers The basic versions of the fixed circuit-breakers are three-pole and fitted with: EL type manual operating mechanism mechanical signalling device for closing springs charged/discharged mechanical signalling device for circuit-breaker open/closed closing pushbutton opening pushbutton operation counter set of ten circuit-breaker open/closed auxiliary contacts. Note: with the group of ten auxiliary contacts, as standard, and the maximum of the requested applications, the following are available: three opening contacts (signalling circuit-breaker open) and five closing contacts (signalling circuit-breaker closed). lever for manual closing spring charging auxiliary circuit support terminal box. 9

12 5.4. Withdrawable circuit-breaker The withdrawable circuit-breakers (see fig. 5) are available for UniGear type ZS1 and UniSafe switchgear. They consist of a truck on which the supporting structure of the circuit-breaker is fixed. The cord with the connector (14) (plug) for connection of the operating mechanism electrical accessories comes out of the connection (15). The strikers for operating the contacts (connected/isolated) located in the switchgear are fixed in the top part of the circuit-breaker. The slides (9) for operating the segregation shutters of the medium voltage contacts of the switchgear enclosure are fixed on the sides of the circuit-breaker. On the front part of the circuit-breaker truck, the crosspiece is mounted with the handles (17) for hooking up the circuit-breaker for the racking-in/ out operations by means of the special operating lever (16). The circuit-breaker is completed with the isolating contacts (8). The withdrawable circuit-breaker is fitted with special locks on the front crosspiece, which allow hooking up into the corresponding couplings of the switchgear. The locks can only be activated by the handles with the truck fully resting against the crosspiece. The operating lever (16) must be fully inserted (also see par. 7.5.). A lock prevents the truck from advancing into the enclosure or fixed part when the earthing switch is closed. Another lock prevents racking-in and racking-out with the circuit-breaker closed. With the truck in an intermediate position between isolated and connected, a further lock prevents circuit-breaker closing (either mechanical or electrical). A locking magnet is also mounted on the truck which, when de-energised, prevents the truck racking-in operation. On request, an interlock is also available which prevents racking-in of the circuit-breaker with the door open, and door opening with the circuitbreaker closed General characteristics of withdrawable circuit-breakers for UniGear ZS1 type switchgear (1) Rated uninterrupted currents guaranteed with withdrawable circuit-breakers installed in UniGear ZS1 type switchgear with air temperature of 40 C. (2) The rated uninterrupted current of 2300 A is guaranteed with natural ventilation. The rated uninterrupted current of 2500 A is guaranteed with forced ventilation. Circuit-breaker Standards Rated voltage Rated insulation voltage Withstand voltage at 50 Hz Impulse withstand voltage Rated frequency Rated normal current (40 C) Rated breaking capacity (rated symmetrical short-circuit current) Rated short-time withstand current (3 s) Making capacity Operation sequence Opening time Arcing time Total breaking time Closing time Maximum overall dimensions Pole centre distance Standardised table of dimensions Operating temperature Tropicalisation Electromagnetic compatibility Ur [kv] Us [kv] Ud (1 min) [kv] Up [kv] fr [Hz] (1) Ir [A] Isc [ka] Ik [ka] Ip [ka] [O-0,3s-CO-3min-CO] [ms] [ms] [ms] [ms] H [mm] W [mm] D [mm] I [mm] [ C] VD4/P 12 IEC ; CEI 17-1 (File 1375) TN7412 TN7412 TN7415 TN7416 TN7415 TN7416 TN IEC: ; IEC: 60694, ;

13 Caption 1 Lever for manually charging the closing springs 2 Signalling device for circuit-breaker open/ closed 3 Rating plate 4 Opening pushbutton 5 Closing pushbutton Fig. 5 6 Signalling device for closing springs charged/ discharged 7 Operation counter 8 Isolating contacts 9 Slide for operating the switchgear shutters 10 Truck 11 Locks for hooking into the fixed part 12 Mechanical override for undervoltage release (optional) 13 Strikers for activating the contacts placed in the enclosure 14 Connector (plug) 15 Cabling connection 16 Operating lever of circuit-breaker rackingin/out 17 Handles for activating the locks (11) VD4/P 17 IEC ; CEI 17-1 (File 1375) VD4/P 24 IEC ; CEI 17-1 (File 1375) (2) TN7412 TN7412 TN7415 TN7416 TN7415 TN7416 TN IEC: ; IEC: 60694, ; TN7413 TN7414 TN7413 TN7414 TN7418 TN7418 TN IEC: ; IEC: 60694, ;

14 Types of withdrawable circuit-breakers available for UniGear type ZS1 switchgear VD4/P withdrawable circuit-breaker for UniGear type ZS1 switchgear Ur Isc Rated uninterrupted current (40 C) [A] kv ka W = 650 W = 800 W = 1000 W = 1000 W = 800 W = 1000 W = 1000 Circuit-breaker type I = 150 I = 210 I = 275 I = 275 I = 210 I = 275 I = 275 u/l = 205 u/l = 310 u/l = 310 u/l = 310 u/l = 310 u/l = 310 u/l = 310 ø = 35 ø = 79 ø = 79 ø = 109 ø = 35 ø = 35 ø = VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p275 Notes W = Width of the switchgear. I = Pole horizontal centre distance. u/l= Distance between bottom and top terminal. ø = Diameter of the isolating contact. 12

15 VD4/P withdrawable circuit-breaker for UniGear type ZS1 switchgear Ur Isc Rated uninterrupted current (40 C) [A] kv ka W = 650 W = 800 W = 1000 W = 1000 W = 800 W = 1000 W = 1000 Circuit-breaker type I = 150 I = 210 I = 275 I = 275 I = 210 I = 275 I = 275 u/l = 205 u/l = 310 u/l = 310 u/l = 310 u/l = 310 u/l = 310 u/l = 310 ø = 35 ø = 79 ø = 79 ø = 109 ø = 35 ø = 35 ø = VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p (*) VD4/P p (*) VD4/P p (*) VD4/P p275 Notes W = Width of the switchgear. I = Pole horizontal centre distance. u/l= Distance between bottom and top terminal. ø = Diameter of the isolating contact. (*) The rated current of 2300A is guaranteed with natural ventilation. The rated current of 2500A is guaranteed with forced ventilation Standard fittings for withdrawable circuit-breakers for UniGear type ZS1 switchgear The basic versions of the withdrawable circuit-breakers are three-pole and fitted with: EL type manual operating mechanism mechanical signalling device for closing springs charged/discharged mechanical signalling device for circuit-breaker open/closed closing pushbutton opening pushbutton operation counter set of ten circuit-breaker open/closed auxiliary contacts. Note: with the group of ten auxiliary contacts, as standard, and the maximum of the requested applications, the following are available: three opening contacts (signalling circuit-breaker open) and five closing contacts (signalling circuit-breaker closed). lever for manually charging the closing springs isolating contacts cord with connector (plug only) for auxiliary circuits, with striker pin which does not allow connection of the plug in the socket if the rated current of the circuit-breaker is different from the rated current of the panel racking-in/out lever (the quantity must be defined according to the number of pieces of apparatus ordered) locking electromagnet in the truck. It prevents racking-in of the circuitbreaker in the panel with auxiliary circuits not connected (plug not inserted in the socket). 13

16 General characteristics of withdrawable circuit-breakers for UniSafe switchgear Circuit-breaker Standards Rated voltage Rated insulation voltage Withstand voltage at 50 Hz Impulse withstand voltage Rated frequency Rated normal current (40 C) Rated breaking capacity (rated symmetrical short-circuit current) Rated short-time withstand current (3 s) Making capacity Operation sequence Opening time Arcing time Total breaking time Closing time Maximum overall dimensions Pole centre distance Standardised table of dimensions Operating temperature Tropicalisation Electromagnetic compatibility IEC CEI 17-1 (File 1375) Ur [kv] Us [kv] Ud (1 min) [kv] Up [kv] fr [Hz] (1) Ir [A] Isc [ka] Ik [ka] Ip [ka] [O-0,3s-CO-3min-CO] [ms] [ms] [ms] [ms] H [mm] W [mm] D [mm] I [mm] [ C] IEC: IEC: 60694, VD4/P TN7412 TN7412 TN7420 TN7420 TN7415 TN7415 TN (1) Rated uninterrupted currents guaranteed with withdrawable circuit-breakers installed in UniSafe switchgear with air temperature of 40 C. 14

17 VD4/P 17 VD4/P TN7412 TN7412 TN7420 TN7420 TN7415 TN7415 TN TN7413 TN7413 TN7418 TN

18 Types of withdrawable circuit-breakers available for UniSafe switchgear VD4/P withdrawable circuit-breaker for UniSafe switchgear Ur Isc Rated uninterrupted current (40 C) [A] kv ka W = 600 W = 750 W = 750 W = 1000 W = 800 W = 1000 Circuit-breaker type I = 150 I = 210 I = 210 I = 275 I = 210 I = 275 u/l = 205 u/l = 310 u/l = 310 u/l = 310 u/l = 310 u/l = 310 ø = 35 ø = 35 ø = 79 ø = 109 ø = 35 ø = VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/W p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p VD4/P p275 Notes W = Width of the switchgear. I = Pole horizontal centre distance. u/l= Distance between bottom and top terminal. ø = Diameter of the isolating contact. 16

19 Standard fittings for withdrawable circuit-breakers for UniSafe switchgear The basic versions of the withdrawable circuit-breakers are always three-pole and fitted with: EL type manual operating mechanism mechanical signalling device for closing springs charged/discharged mechanical signalling device for circuit-breaker open/closed closing pushbutton opening pushbutton operation counter set of ten circuit-breaker open/closed auxiliary contacts. Note: with the group of ten auxiliary contacts, as standard, and the maximum of the requested applications, the following are available: three opening contacts (signalling circuit-breaker open) and five closing contacts (signalling circuit-breaker closed). lever for manually charging the closing springs isolating contacts cord with connector (only plug) for auxiliary circuits, with striker pin which does not allow connection of the plug in the socket if the rated current of the circuit-breaker is different from the rated current of the panel racking-in/out lever (the quantity must be defined according to the number of pieces of apparatus ordered) locking electromagnet in the truck. It prevents racking-in of the circuit-breaker in the panel with auxiliary circuits not connected (plug not inserted in the socket). 17

20 5.5. Characteristics of the electrical accessories Shunt opening release (-M01); Additional shunt opening release (-M02); Shunt closing release (-MC) Un: V Un: V~ 50 Hz Un: V~ 60 Hz Operating limits: % Un Inrush power (Ps): DC 200 W; AC = 200 VA Inrush time approx. 100 ms Maintenance power (Pc): DC = 5 W; AC = 5 VA Opening time: ms Closing time: ms Insulation voltage: 2500 V 50 Hz (for 1 min) Undervoltage release (-MU) Un: V Un: V~ 50 Hz Un: V~ 60 Hz Operating limits: circuit-breaker opening: 35-70% Un circuit-breaker closing: % Un Inrush power (Ps): DC 200 W; AC = 200 VA Inrush time approx. 100 ms Maintenance power (Pc): DC = 5 W; AC = 5 VA Opening time: 30 ms Insulation voltage: 2500 V 50 Hz (for 1 min) Electronic time delay device for undervoltage release (mounted outside the circuit-breaker) Un: V Un: V~ 50/60 Hz Adjustable opening time (release + time delay device): s Motor for motorised truck (-MT) (only for withdrawable circuit-breaker for UniGear Type ZS1 switchgear) Un: V DC Operating limits: % Un Rated Power (Pn): 40 W Auxiliary contacts of the circuit-breaker Un: V AC-DC Rated current: Insulation voltage: Ith 2 = 10 A 2500 V 50 Hz (for 1 min) Electrical resistance: 3 mohm Rated current and breaking capacity in category AC11 and DC11: Un Cosj T In Icu 220 V ~ A 25 A 24 V ms 10 A 12 A 60 V ms 6 A 8 A 110 V ms 4 A 5 A 220 V ms 1 A 2 A Note With the group of 10 auxiliary contacts supplied as standard, the following are available: for the fixed circuit-breaker: 3 NO contacts + 5 NC contacts for the withdrawable circuit-breaker: 3 NO contacts + 4 NC contacts. With the group of 15 auxiliary contacts (+ 5 contacts on request compared with the 10 supplied as standard), the following are available: for the fixed circuit-breaker, at choice: 6 NO contacts + 7 NC contacts or 8 NO contacts + 5 NC contacts or 5 NO contacts + 8 NC contacts or 3 NO contacts + 10 NC contacts for the withdrawable circuit-breaker, the following are available, according to the required applications, from a maximum of 6 NO contacts + 6 NC contacts to a minimum of 5 NO contacts + 5 NC contacts. Motor operator (-MS) Un: V Un: V~ 50/60 Hz Operating limits: % Un Inrush power (Ps): DC 500 W; AC = 500 VA Rated power (Pn): Inrush time Charging time: Insulation voltage: DC = 200 W; AC = 200VA 0,2 s 4-5 s 2500 V 50 Hz (for 1 min) Locking magnet on the operating mechanism (-RL1) Un: V Un: V~ 50/60 Hz Operating limits: % Un Inrush power (Ps): DC 250 W; AC = 250 VA Continuous power (Pc): Inrush time: DC = 5 W; AC = 5 VA 150 ms Locking magnet on the truck (-RL2) Un: V Un: V~ 50/ 60 Hz Operating limits: % Un Inrush power (Ps): DC 250 W; AC = 250 VA Continuous power (Pc): Inrush time: DC = 5 W; AC = 5 VA 150 ms 18

21 6. Instructions for operating the circuit-breaker 6.1. Safety indications! The VD4 circuit-breakers guarantee a minimum IP2X degree of protection when installed in the following conditions: fixed version, installed behind metallic grid withdrawable version, installed in switchgear. Under these conditions the operator is totally guaranteed against accidental contact with moving parts. Should mechanical operations be carried out on the circuit-breaker outside the switchgear, be very careful of the moving parts. If the operations are prevented, do not force the mechanical interlocks and check that the operating sequence is correct. Racking the circuit-breaker in and out of the switchgear must be done gradually to avoid shocks which may deform the mechanical interlocks Operating and signalling parts Mechanical override for undervoltage release (optional) Undervoltage release deactivated. The circuitbreaker can be closed even if the undervoltage release is de-energised. Undervoltage release activated. The circuitbreaker can be closed only if the undervoltage release is energised Caption 1 Key lock (if provided). 2 Lever for manually charging the closing springs. 3 Coupling lever for racking-out operation (only for withdrawable circuit-breakers). 4 Opening pushbutton. 5 Closing pushbutton. 6 Signalling device for circuit-breaker open/closed. 7 Signalling device for closing springs charged/discharged. 8 Operation counter. 9 Handles for operating the truck locks (only for withdrawable circuit-breakers). 10 Operating lever for circuit-breaker racking-in/out. 11 Mechanical override for undervoltage release (optional). 10 Fig. 6 19

22 6.3. Circuit-breaker closing and opening operations Circuit-breaker operation can be either manual or electrical (fig. 6 - fig. 7). a) Manual spring charging operation To manually charge the closing springs, it is necessary to repeatedly activate the charging lever (2) (maximum rotation angle of the lever: about 90 ) until the yellow signalling device (7) appears which indicates completion of charging. The maximum forces which can normally be applied to the lever are <150 N for the EL1operating mechanism and <200 N for the EL2 operating mechanism. For the type of operating mechanism, please refer to the rating plate in fig. 1. b) Electrical spring charging operation On request, the circuit-breaker can be fitted with the following accessories for electrical operation: geared motor for automatic closing spring charging shunt closing release shunt opening release. The geared motor automatically recharges the springs after each closing operation until the yellow signalling device (7) appears. If the power is cut off during charging, the geared motor stops and automatically starts recharging the springs again when the power returns. In any case, it is always possible to complete the recharging operation manually. c) Circuit-breaker closing The operation can only be carried out with the closing springs completely charged. For manual closing, press the pushbutton (5). When there is a shunt closing release, the operation can also be carried out remotely by means of a special control circuit. Closing having taken place is indicated by the signalling device (6). d) Circuit-breaker opening For manual opening, press the pushbutton (4). When there is a shunt opening release, the operation can also be carried out remotely by means of a special control circuit. Opening having taken place is indicated by the signalling device (6). 7» 90 2 Fig. 7 20

23 7. Installation 7.1. General! Correct installation is of primary importance. The manufacturer s instructions must be carefully studied and followed. It is good practice to use gloves for handling the pieces during installation Installation and service conditions The following Standards must be taken into particular consideration during installation and service: IEC60694/DIN VDE 0101 VDE 0105: Electrical installation service DIN VDE 0141: Earthing systems for installations with rated voltage above 1 kv All the accident prevention regulations in force in the relative countries Special conditions Installations over 1000 m a.s.l. Possible within the limits permitted by reduction of the dielectric resistance of the air. Increase in the ambient temperature Reduction in the rated current. Encourage heat dissipation with appropriate additional ventilation. Climate To avoid the risk of corrosion or other damage in areas: with a high level of humidity, and/or with rapid and big temperature variations, take appropriate steps (for example, by using suitable electric heaters) to prevent condensation phenomena. For special installation requirements or other operating conditions, please contact ABB Normal conditions Follow the recommendations in the IEC and Standards. In more detail:! The areas involved by the passage of power conductors or conductors of auxiliary circuits must be protected against access of any animals which might cause damage or disservices. Ambient temperature Maximum + 40 C Average maximum over 24 hours + 35 C Minimum (according to class 5), apparatus for indoor installation 5 Humidity The average value of the relative humidity, measured for a period longer than 24 hours, must not exceed 95%. The average value of the water vapour pressure, measured for a period longer than 24 hours, must not exceed 2.2 kpa. The average value of the relative humidity, measured for a period longer than 1 month, must not exceed 90%. The average value of the water vapour pressure, measured for a period longer than 1 month, must not exceed 1.8 kpa. Altitude < 1000 m above sea level. 21

24 Curves of permissible numbers of switching cycles The following graphs show the number of closing-opening cycles (No.) allowed, of the vacuum interrupters, according to the breaking capacity (Ia). N. N. Fig. 8a Fig. 8b N. N. Caption No. Number of closingopening cycles allowed for the vacuum interrupters. Ia Breaking capacity of the vacuum interrupters. 22 Fig. 8c Fig. 8d

25 N. N. Fig. 8e Fig. 8f N. N. Fig. 8g Fig. 8h Caption No. Number of closingopening cycles allowed for the vacuum interrupters. Ia Breaking capacity of the vacuum interrupters. 23

26 7.3. Preliminary operations Clean the insulating parts with clean dry cloths. Check that the top and bottom terminals are clean and free of any deformation caused by shocks received during transport or storage Installation of fixed circuit-breakers The circuit-breaker can be mounted directly on supporting frames to be provided by the customer, or on a special supporting truck (available on request). The circuit-breaker, with supporting truck, must be suitably fixed to the floor of its own compartment by the customer. The floor surface in correspondence with the truck wheels must be carefully levelled. A minimum degree of protection (IP2X) must be guaranteed from the front towards live parts Mounting the circuit-breaker on trucks constructed by other manufacturers VD4 circuit-breakers which are not installed on ABB trucks, but on trucks constructed by the customer must be fitted with one or two additional auxiliary contacts (activated by the mechanical lock and by the circuit-breaker trip device) entrusted with the function of interrupting the shunt closing release circuit release (-MC). In ABB trucks, this function is carried out by the auxiliary contacts -BT1 and -BT2 which cut of the release power supply during and before activation of the mechanical lock of the screw device for racking the truck in. This means the shunt closing release power supply can only be applied after activation of the mechanical lock. In this way there is the certainty that no electrical impulse can activate the shunt closing release with the circuit-breaker in the intermediate position Installation of withdrawable circuitbreakers The withdrawable circuit-breakers are preset for use in UniGear type ZS1 and UniSafe switchgear. For racking-in/racking-out of the switchgear, fully insert the lever (1) (fig. 9) in the appropriate seat (2) and work it clockwise for racking-in, and anticlockwise for racking-out, until the limit switch positions are reached. Circuit-breaker racking-in/-out must be carried out gradually to avoid shocks which may deform the mechanical interlocks and the limit switches. The torque normally required to carry out racking-in and racking-out is 25 Nm. This value must not be exceeded. If operations are prevented or difficult, do not force them and check that the operating sequence is correct. Note To complete the racking-in/out operation, about 20 rotations of the lever are required for circuitbreakers up to 17.5 kv, and about 30 rotations for 24 kv circuit-breakers. When the circuit-breaker has reached the isolated for test/isolated position, it is positively connected to the panel, and it is earthed by means of the truck wheels. Withdrawable circuit-breakers of the same version, and therefore of the same dimensions, are interchangeable. However, when different fitting of electrical accessories is foreseen, for example, different coding of the auxiliary circuit plug prevents incorrect combinations between circuit-breakers and panels.! The racking-in/-out operations must always be carried out with the circuitbreaker open Circuit-breakers with motorised with - drawable truck (on request, and only for use in UniGear ZS1 type switchgear). Note: at 24 kv, it is only available for 630 A / 1250 A with 210 mm pole centre distance. Test the motor-driven truck in the same way as a truck with manual racking-in: turn off the truck motor circuit power supply to lock it electrically; turn the crank handle (1) (fig. 9) to the desired position. Note When the moving part moves, it makes the motor turn, which, acting like a generator, can cause a reverse voltage at the connection terminals. 24

27 Check the direction of rotation of the motordriven truck: by means of the crank handle (1), manually put the withdrawable circuit-breaker in the central position of the guides (between the test / disconnected position and the service position); remove the crank handle (1); supply the truck motor circuit; using the switchgear local electrical controls, check that the truck traverses in the correct directions.! When the direction of movement is not correct, do not allow withdrawable part to force a lock! Switch the motor power supply off immediately (truck stopping is normally ensured by a limit switch). Should the switchgear door be open, there could be a hazard for personnel. Motor-driven truck operations Operate the electrical racking-in and out controls (the withdrawable circuit-breaker traverses in the directions indicated by the controls). Check the position indicators. Note When the motor fails, the truck can operated manually in an emergency. If the motor fails during a racking in/out operation, the truck can be taken to the run end manually in an emergency. Use the crank handle (1) for emergency operations, inserting it into the special coupling (2), and work in the same way as with a truck with manual racking-in: turn off the truck motor circuit power supply to lock it electrically; turn the crank handle (1) (fig. 9) to the desired position.! When the moving part moves, it makes the motor turn, which, acting like a generator, can cause a reverse voltage at the connection terminals. The motor protection device must be replaced with a new one with identical characteristics, otherwise the permanent magnet of the motor could be irreparably damaged. Racking-in 2 Max. 25 Nm 1 Racking-out Fig. 9 25

28 7.6. Power circuit connections of fixed circuit-breakers General recommendations Select the cross-section of the conductors according to the service current and the shortcircuit current of the installation. Prepare special pole insulators, near the terminals of the fixed circuit-breaker or of the enclosure, sized according to the electrodynamic forces deriving from the short-circuit current of the installation Assembly of the connections Check that the contact surfaces of the connections are flat, and are free of any burrs, traces of oxidation or deformation caused by drilling or impacts received. According to the conductor material and the surface treatment used, carry out the operations indicated in table T1 on the contact surface of the conductor. Assembly procedure Put the connections in contact with the circuitbreaker terminals taking care to avoid mechanical stresses (traction / compression) on, for example, the conducting busbars on the terminals. Interpose a spring washer and a flat washer between the head of the bolt and the connection. It is advisable to use bolts according to DIN class 8.8 Standards, also referring to what is indicated in table T2. In the case of cable connections, strictly follow the manufacturer s instructions to make the terminals. T1 Bare copper Clean with a fine file or emery cloth. Tighten fully and cover the contact surfaces with 5RX Moly type grease. Copper or silver-plated aluminium Clean with a rough dry cloth. Only in the case of obstinate traces of oxidation, clean with a very fine grain emery cloth taking care not to remove the surface layer. If necessary, restore the surface treatment. Bare aluminium Clean with a metal brush or emery cloth Cover the contact surfaces again immediately with neutral grease. Insert the copper-aluminium bimetal with surfaces shined (copper side in contact with the terminal; aluminium side in contact with the connection) between the aluminium connection and the copper terminal. T2 Bolt M6 M8 M10 M12 M16 Recommended tightening torque (1) Without lubricant With lubricant (2) 10.5 Nm 4.5 Nm 26 Nm 10 Nm 50 Nm 20 Nm 86 Nm 40 Nm 200 Nm 80 Nm (1) The nominal tightening torque is based on a friction coefficient of the thread of 0.14 (distributed value the thread is subjected to which, in some cases, is not negligible). The nominal tightening torque with lubricant is according to the DIN Standards. (2) Oil or grease. The thread and surfaces in contact with the lubricated heads. Take into account the deviations from the general Standards table (for example, for systems in contact or terminals) as foreseen in the specific technical documentation. The thread and surfaces in contact with the heads of bolts must be slightly oiled or greased, so as to obtain correct nominal tightening torque. 26

29 7.7. Earthing For the fixed version circuit-breaker, carry out earthing by means of the special screws marked with the relative symbol. Clean and degrease the area around the screw to a diameter of about 30 mm and, on completion of assembly, cover the joint again with Vaseline grease. Use a conductor (busbar or cord) with a crosssection conforming with the Standards in force Connection of the auxiliary circuits Note: the minimum cross-section of the wires used for the auxiliary circuits must not be less than the one used for the internal cabling. Furthermore, they must be insulated for 3 kv test Fixed circuit-breaker Connection of the circuit-breaker auxiliary circuits must be made by means of the terminal box (1) (fig. 10) mounted inside the circuit-breaker and the cables must pass through the connector (2). Outside the connector, the cables must pass through a suitable metal protective cover (pipe, wiring duct, etc.) which must be earthed. To prevent the cabling wires outside the circuitbreaker (provided by the customer) accidentally coming into contact with moving parts and therefore damaging the insulation, it is recommended to position and fix the cables as indicated in fig. 10a.! Before removing the operating mechanism cover to access the terminal box, check that the circuit-breaker is open and the closing springs discharged. 1 2 Fig. 10 Fig. 10a 27

30 Withdrawable circuit-breakers The auxiliary circuits of withdrawable circuitbreakers are fully cabled in the factory as far as the connector (fig. 11). For the external connections, refer to the electric wiring diagram of the switchgear. Fig

31 7.9. Overall dimensions Fixed circuit-breakers VD4 TN 7405 Ur 12 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka A A 2X M M 12 VD4 TN 7405 Ur 17.5 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka (*) (*) (*) Interchangeability of fixing with the previous series (345 x 400). VD4 TN 7406 Ur 12 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka A XM10 A M VD4 TN 7406 Ur 17.5 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka (*) (*) (*) Interchangeability of fixing with the previous series (345 x 520). 29

32 Fixed circuit-breakers VD4 TN 7407 Ur 12 kv Ir 1600 A 2000 A Isc 20 ka 25 ka 31.5 ka VD4 TN 7407 Ur 17.5 kv Ir 1600 A 2000 A Isc 20 ka 25 ka 31.5 ka (*) A (*) A xM10 4xM (*)Interchangeability of fixing with the previous series (345 x 520) VD4 TN 7408 Ur 12 kv Ir 1600 A 2000 A 2500 A Isc 20 ka 25 ka 31.5 ka A x M 10 4xM (*) A VD4 TN 7408 Ur 17.5 kv Ir 1600 A 2000 A 2500 A Isc 20 ka 25 ka 31.5 ka (*) (*) Interchangeability of fixing with the previous series (345 x 650). 30

33 Fixed circuit-breakers VD4 TN 7409 Ur 24 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka A A 2 x M M (*) M12 345(*) (*) Interchangeability of fixing with the previous series (345 x 520) VD4 TN 7410 Ur 24 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka A A xM M (*) 345 (*) (*) Interchangeability of fixing with the previous series (345 x 650). 31

34 Fixed circuit-breakers VD4 TN 7411 Ur 24 kv Ir 1600 A 2000 A Isc 16 ka 20 ka 25 ka VD4 TN 7411 Ur 24 kv Ir 2500 A Isc 25 ka (*) A (*) A xM xM (*) Interchangeability of fixing with the previous series (345 x 650). 32

35 Withdrawable circuit-breakers for UniGear type ZS1 switchgear and UniSafe switchgear VD4/P TN 7412 Ur 12 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka VD4/P TN 7412 Ur 17,5 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka VD4/W (1) TN 7420 Ur 12 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka VD4/W (1) TN 7420 Ur 17.5 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka 31.5 ka n (1) Only for UniSafe switchgear. 33

36 Withdrawable circuit-breakers for UniGear type ZS1 switchgear and UniSafe switchgear VD4/P TN 7415 Ur 12 kv Ir 1600 A 2000 A Isc 20 ka 25 ka 31.5 ka VD4/P TN 7415 Ur 17.5 kv Ir 1600 A 2000 A Isc 20 ka 25 ka 31.5 ka VD4/P (1) TN 7416 Ur 12 kv Ir 1600 A 2000 A Isc 20 ka 25 ka 31.5 ka VD4/P (1) TN 7416 Ur 17.5 kv Ir 1600 A 2000 A Isc 20 ka 25 ka 31.5 ka (1) Only for UniGear ZS1 type switchgear. 34

37 Withdrawable circuit-breakers for UniGear type ZS1 switchgear and UniSafe switchgear VD4/P TN 7417 Ur 17.5 kv Ir 2500 A Isc 20 ka 25 ka 31.5 ka VD4/P TN 7413 Ur 24 kv Ir 630 A 1250 A Isc 20 ka 25 ka 31.5 ka

38 Withdrawable circuit-breakers for UniGear type ZS1 switchgear and UniSafe switchgear VD4/P (1) TN 7414 Ur 24 kv Ir 630 A 1250 A Isc 16 ka 20 ka 25 ka (1) Only for UniGear type ZS1 switchgear. VD4/P TN 7418 Ur 24 kv Ir 1600 A 2000 A 2500 A (2) Isc 16 ka 20 ka 25 ka (2) Only for UniGear ZS1 type switchgear. The rated uninterrupted current of 2300 A is guaranteed with natural ventilation. The rated uninterrupted current of 2500 A is guaranteed with forced ventilation

39 8. Putting into service 8.1. General procedures! All the operations regarding putting into service must be carried out by ABB personnel or by suitably qualified customer personnel with in-depth knowledge of the apparatus and of the installation. Should the operations be prevented, do not force the mechanical interlocks and check that the operating sequence is correct. The operating forces which can be applied for racking-in withdrawable circuit-breakers are indicated in paragraph 7.5. Before putting the circuit-breaker into service, carry out the following operations: check tightness of the power connections to the circuit-breaker terminals; establish the setting of the primary electronic overcurrent release (if provided); check that the value of the power supply voltage of the auxiliary circuits is between 85% and 110% of the rated voltage of the electrical accessories; check that no foreign bodies, such as bits of packing, have got into the moving parts; check that there is a sufficient exchange of air in the installation place to avoid overtemperatures; also carry out the checks indicated in table T3. T3 ITEM INSPECTED PROCEDURE POSITIVE CHECK 1 Insulation resistance. Medium voltage circuit With a 2500 V megger, measure the insulation resistance between the phases and the exposed conductive part of the circuit. The insulation resistance should be at least 50 Mohm and in any case constant over time Auxiliary circuits. Manual operating mechanism. Motor operator (if provided). Undervoltage release (if provided). Auxiliary circuits With a 500 V megger (if the apparatus installed allows this), measure the insulation resistance between the auxiliary circuits and the exposed conductive part. Check that the connections to the control circuit are correct: proceed at the relative power supply. Carry out a few closing and opening operations (see chap. 6). N.B. Supply the undervoltage release and the locking magnet on the operating mechanism at the relative rated voltage (if provided). Supply the spring charging geared motor at the relative rated voltage. Carry out a few closing and opening operations. N.B. Supply the undervoltage release and the locking magnet on the operating mechanism at the relative rated voltage (if provided). Supply the undervoltage release at the relative rated voltage and carry out the circuit-breaker closing operation. The insulation resistance should be a few Mohm and in any case constant over time. Operations and signals normal. The operations and the relative signals take place normally. The springs are charged normally. The signals are normal. With the springs charged, the geared motor stops. The geared motor recharges the springs after each closing operation. The circuit-breaker closes normally. The signals are normal. Cut off power to the release. The circuit-breaker opens. The signal changes over. 6 7 Shunt opening release and additional shunt opening release (if provided). Shunt closing release (if provided). Close the circuit-breaker and supply the shunt opening release at the relative rated voltage. Open the circuit-breaker and supply the shunt closing release at the relative rated voltage. The circuit-breaker opens normally. The signals are normal. The circuit-breaker closes normally. The signals are normal. 37

40 T3 ITEM INSPECTED PROCEDURE POSITIVE CHECK Key lock (if provided). Locking electromagnet (-RL1) (if provided). Auxiliary contacts in the operating mechanism. Locking electromagnet on the truck circuit-breaker (-RL2) (if provided). Auxiliary transmitted contacts for signalling circuit-breaker racked-in, isolated (UniGear or UniSafe switchgear). Open the circuit-breaker. Turn the key and remove it. Attempt the circuit-breaker closing operation. Put the key back in and turn it 90. Carry out the closing operation. With the circuit-breaker open, springs charged and locking electromagnet not supplied, attempt circuit-breaker closing both manually and electrically. Insert the auxiliary contacts in suitable signalling circuits. Carry out a few closing and opening operations. With the circuit-breaker open, in the isolated for test position and the locking electromagnet not supplied, attempt racking-in of the circuit-breaker. Supply the locking electromagnet and carry out the racking-in operation. Insert the auxiliary contacts in suitable signalling circuits. With the circuit-breaker racked into the enclosure, carry out a few traverse operations from the isolated for test position to the connected position. Take the circuit-breaker to the racked-out position. Neither manual or electrical closing takes place. Both electrical and manual closing take place normally; in this position the key cannot be removed. Closing is not possible. Signals take place normally. Racking-in is not possible. Racking-in takes place correctly. The signals due to the relative operations take place normally. 38

41 9. Maintenance Maintenance operations are aimed at ensuring trouble-free operation of the apparatus for the longest possible time. In accordance with the specifications of the IEC / DIN Standards, the following operations must be carried out. Inspection: Determination of the actual conditions Servicing: Measures to maintain the specified conditions Repair: Measures to restore the specified conditions General Vacuum circuit-breakers are characterized by their simple and sturdy construction and long life. The operating mechanism does not require maintenance for the whole operating lite. Only functional inspections are needed. The vacuum interrupters are maintenance-free for their whole operating life. Vacuum interruption does not cause any harmful effects even in the presence of frequent trips at the rated and short-circuit currents. The servicing interventions and their aim depend on environmental conditions, the sequence of operations and trips under short-circuit. Note The following Standards must be observed for all maintenance work: the relevant specifications indicated in the Standards and specifications chapter; the safety in the work place regulations given in the Putting into service and Operation chapter; the standards and specifications in the country of installation. Maintenance work can only be performed by trained personnel, observing all the safety regulations. It is recommended that ABB service personnel should be called in, at least to check the service performances and for repair work. While the work is in progress, turn the power supply off and put the apparatus under safe conditions.! Before carrying out any operations, check that the circuit-breaker is open, with the springs discharged and that it is not supplied (medium voltage circuit and auxiliary circuits) Operating life Typical life-expectancies for VD4 circuit-breakers: vacuum interrupters: up to 30,000 operations, depending on their type (see paragraph ); actuator: up to 30,000 operations under normal operating conditions, depending on the type of circuit-breaker and with regular maintenance Inspection and functional testing Interruption devices in general Carry out regular inspections to verify the good condition of the interruption devices. Inspection at fixed intervals can be waived if the switchgear is permanently monitored by qualified personnel. Above all, the checks must include a visual inspection to find any contamination, traces of corrosion and electrical discharge phenomena. When there are unusual operating conditions (including adverse climatic conditions) and/or in the case of environmental pollution (e.g. heavy contamination or an atmosphere with aggressive agents), inspection must be carried out more frequently. Visual examination of the isolating contacts. Turning the contacts alternately is recommended, in order to keep the internal surface of the contact areas clean. The contact areas must be cleaned if there are signs of overheating (discoloured surface) (also see the paragraph on Repairs ). If any anomalous conditions are found, appropriate servicing measures must be taken (see the paragraph on Servicing ). 39

42 Stored-energy spring operating mechanism Carry out the functional testing of the operating mechanism is to be performed after 5,000 operating cycles or after 4 years. Before the test, open the circuit-breaker and carry out the following operations: for withdrawable circuit-breakers, put the circuit-breaker in the isolated for test position for fixed circuit-breakers, cut off the power supply to the medium voltage circuit. Note Insulate the working area and make it safe, following the safety regulations specified in the IEC/ DIN VDE Standards. Checking locking of screws Aim of functional testing With the circuit-breaker disconnected from the load, carry out several opening and closing operations. Turn the power to the spring charging motor off (if fitted) and discharge the springs by closing and opening the circuit-breaker using the closing and opening pushbuttons. Visually examine the state of lubrication of the isolating contacts, sliding surfaces, etc. Check correct electrical and mechanical operation of the various devices, paying special attention to the interlocks. The screws and nuts are tightened in the factory and correct tightening is marked with a coloured sign. No further tightening is foreseen during the operating life of the circuit-breaker. However, should it be necessary to retighten any screws or the nuts following any trips, keep to the values indicated in fig Nm 10 Nm 10 Nm 12 Nm 15 Nm 25 Nm 40

43 Check lubrication of the roller bearing of the main lever of the actuator (see details A of fig. 13): it is advisable to lubricate with a few drops of SAE 80W/90 type oil, using a special lubricator. Proceed as follows: load the operating mechanism springs and lubricate the right bearing (circuit-breaker viewed from the front) close the circuit-breaker and lubricate the left bearing (circuit-breaker viewed from the front). Lubricating roller bearings A A Lubricating right bearing (circuit-breaker viewed from the front) A Lubricating left bearing (circuit-breaker viewed from the front) A 41